Has anyone made their own solar panel with rechargeable 12/6 volt battery to hook up to a trail cam?
Can you share how you did it?

I used a Moultrie pack, soldered a connector from Radio Shack that went into the jack, and set it all out. My experience, squirrels and cows and other critters love to chew on wires. Secured all the wires with flexible conduit after repairs, accidentaly soldered the positive to the negative on the connector. Redid that, and then it ran for a few months, then I showed up and it inexplicably had water in the little sealed off battery pack holder that Moultrie sells. Battery dead. Replaced the battery, ran for a few months, showed up and it was full of water again, battery dead. Gave up, shot the Moultrie Battery back thing, and now I just use better cameras that take AA batteries and last forever. I have a Bushnell Game Cam that I cannot find anywhere that works like a champ. I have used most manufacturers cheap cams, and some that were a little more, like $100, and had so many problems I was about to give up until I got this Bushnell cheap, but I have searched high and low and never found this model again. I guess it worked too good so they upgraded it. :-(

I am doing this today..
my camera is a Minox DTC 1000 cel cam and it uses 8 AAs..
I just put it out a month ago and I am afraid seraching for a cel signal (which it unfortunately doesn't pick up) is going to wear the batteries down fast.

My plan is to the battery in a plastic box with a solar panel and make a cable to plug into the bottom of the unit.
I want to have it up close to the camera or use a small piece of PVC to protect the wires..

I took a 12v 7a battery, WGI solar panel and a box enclosure. I mounted the solar panel to the door of the enclosure and drilled a small hole for the wires to go through and connected it to the batter then connected the battery to the power plug that plugs into the camera. You can mount the camera to the other side of the enclosure and put the enclosure on a pole but I kept the cam and enclosure seperate so I could position each in the direction I wanted to. I did run the plug wires through small steel conduit to keep them from being weathered or eaten. Year and a half and going strong. Make sure to drill the holes on the enclosure on the bottom so water doesn't drip in when it rains. I could have just bought a premade battery/solar panel but this way I can change out the battery when it goes bad and not the entire thing. It also came out cheaper for me plus I got to use a larger battery than what those premade ones come with.

Cool

Most of the cameras use an M size power connector but some may use a different size. Might check to make sure you have the one that works with your camera.

I have six I built on my ranch and they have been working for 5 years, batteries last about 2-3 years running with the solar panels.

Made mine out of an ammo box. Attached solar charger to the outside and put a feeder battery on the inside.

I've built tons of these.
Build or buy or find a box to put the battery in.
I built them out of wood I had laying around.
Put 6 or 12 v battery in it depending on what your camera takes. Most of mine took 12v.
I use this cord:
http://www.amazon.com/gp/aw/d/B001U7KDYK?pc_redir=1406855052&robot_redir=1
It fits my stealth cams and moultrie cams. I've also used plugs from old charger power sources I have laying around and built my own but these have a better connection.
I use this solar panel for 12v:
http://www.amazon.com/gp/aw/d/B00HEFOW2G/ref=pd_aw_sims_1?pi=SS115&simLd=1
I use this one for 6v:
http://www.amazon.com/gp/aw/d/B00HEFP1FI/ref=pd_aw_sims_5?pi=SS115&simLd=1
Build box, drill hole in it for wire, connect wire to battery, put battery in it, screw or tie wire the camera to the box, screw solar panel to box, run charger wire to battery, put screws on edges of box sticking out to tie wire to to hang box and cam. Silicone hole to keep water and bugs out.

I've heard people say to use a diode between the solar panel and the battery to avoid the panel draining power after dark. Anyone have experience with this? Also what is the mA rating on your solar panels and mAH on your batteries?

My camera batteries never went dead so I did not put the diodes in line. I did do it on my feeder setups but they lasted just as long as without.

Heard of it but I didn't

Many newer panels come with the diode built in which is why GLC (and others) may have never had problems; you can always add a diode if not sure- it won't hurt.

The biggest thing that many miss, is that at least once per year (more often if solar-panel is undersized), you should pull the battery and put it on a intellilgent charger for 16+ hours. A solar panel can only 'replentish' charge, and cannot makup a battery that has been depleted. A plain solar panel does not have a regulator in it, and cannot charge the battery to optimum full. NO solar panel can slow-charge the battery for 16 hours to fully-reset the charge to full. Doing this the battery will last 5-7 years.
A rechargeable (SLA) that is low on charge going into a cold winter will actually freeze the electrolyte, destroying the battery immediately.